Abstract：
Scalability of the cooling die unit operation is critical to lowering the manufacturing cost of high moisture meat analogs(HMMA), but it is unclear what scale-up criteria are important. An experiment consisting of two cooling die cross-section geometries (tall and narrow or short and wide), two production rates (2.7 or 4.5 kg/hr) and 4 cooling media inlet temperatures (36, 48, 60, and 72 °C) was employed to study their effect on product texture, anisotropy, and extrusion system parameters. Comprehensive temperature measurements were made along the dies to observe the product temperature gradient and to quantify the energy balance associated with cooling. It was found that textural hardness had a positive relationship with axial temperature gradient (p < 0.05), while anisotropy had a negative and positive relationship with axial temperature gradient and die height, respectively (p < 0.05). Extruder motor torque and die inlet pressure were found to be functions of the cooling media inlet temperature and apparent Newtonian shear rate applied to the material in the die (p < 0.05). The energy balance indicated that enhanced anisotropy is associated with more exothermic in-situ phase changes, which are controlled by the product formulation and applied die conditions. There are likely 3 scalable variables most relevant to controlling the HMMA product quality: 2 critical phase transition temperatures, and the axial product temperature gradient. Therefore, scaling up HMMA cooling dies will require balancing the heat transfer rate away from the product such that an optimal product temperature profile can be maintained at scale.
摘要：
冷却模具单元操作的可扩展性对于降低高水分肉类类似物(HMMA)的制造成本至关重要。但目前还不清楚什么标准是重要的。由两个冷却模具横截面几何形状（高而窄或短而宽）组成的实验，采用两种生产率（2.7或4.5kg/hr）和4种冷却介质入口温度（36、48、60和72°C）来研究它们对产品质地的影响，各向异性，和挤压系统参数。沿模具进行全面的温度测量以观察产品温度梯度并量化与冷却相关的能量平衡。发现组织硬度与轴向温度梯度呈正相关(p<0.05)。而各向异性与轴向温度梯度和模具高度呈正负关系，分别为(p<0.05)。发现挤出机马达扭矩和模具入口压力是冷却介质入口温度和施加到模具中的材料的表观牛顿剪切速率的函数(p<0.05)。能量平衡表明，增强的各向异性与更多的放热原位相变有关，这是由产品配方和应用模具条件控制。可能有3个与控制HMMA产品质量最相关的可扩展变量：2个临界相变温度，和轴向产品温度梯度。因此,按比例放大HMMA冷却模具将需要平衡远离产品的热传递速率,使得可以按比例保持最佳产品温度分布。
